1. Field
Example embodiments relate to a method of doping a field effect transistor including carbon nanotubes as a channel, a method of controlling the position of doping ions, and transistors using the same.
2. Description of the Related Art
Carbon nanotubes (CNTs) are receiving attention as a next generation nano semiconductor material that may replace silicon semiconductors because the CNTs, as a carbon allotrope, have a one-dimensional structure and show a ballistic transportation phenomenon. CNTs have improved mechanical and chemical characteristics, and may be formed to be relatively long in micrometers with a diameter from a few nanometers to a few tens of nanometers, and have increased electrical conductivity, and thus, increased applicability as a fine structure device. Studies have been conducted to apply CNTs to various devices, and thus, CNTs may be presently applied to field emission devices, optical communication fields, and bio devices.
CNTs may be manufactured by using various methods including an arc discharge method, a laser ablation method, a chemical vapor deposition (CVD) method using a catalyst, a screen printing method, or a spin coating method. In order to apply CNTs to semiconductor devices, e.g., complementary metal-oxide-semiconductor (CMOS) transistors, p-type and n-type MOS transistors are required, and CNTs are apt to be p-doped. In the related art, a method of manufacturing an n-type CNT by doping oxygen or potassium ions has been disclosed. However, oxygen ions may not be easily separated from oxygen molecules, and handling the potassium ions may be difficult.